Abstract
This computer aided drug design based conformational and potential energy quantitative structure activity relationship established to find out best fit conformations with minimum potential energy, active structural and molecular sites for strong binding of 3-[3-(N-4- Flurobenzyl-N-2 pyridylamino) propylamino]-4-ethylamino-1, 2, 5- thiazole-1-oxide (C19H23FN6OS) as Histamine H1 receptor antagonist which is previously derived from Cimetidine and extracted by leaves of Espinheria santa. Potential energy calculated for lower limit by Kitagorodasky potential energy function and in-silico approaches. This compound crystalline in monoclinic system, with unit cell dimensions a = 6.686 A˚, b = 14.717 A˚ and c = 20.850 A˚, β = 97.83˚. Present work find out new bond pair (N21--C15) with strong bonding site and suggests that 3-[3-(N-4-Flurobenzyl-N-2 pyridylamino) propylamino]-4-ethylamino-1, 2, 5- thiazole-1- oxide has shown minimum potential energy -0.00000983 Kcal/mole as Histamine H1 receptor antagonist at ω1 = 280˚ and ω2 = 340˚ (Figure-9). It would supports stable and strong binding of antihistaminic compound to their receptors in allowed active region. The compound (C19H23FN6OS) in this active conformation would be helpful for the treatment of allergy and different kind of ulcers such as stomach and duodenum ulcers.
